CVE-2025-21596

CVE-2025-21596 is a medium-severity vulnerability in Juniper Junos with a CVSS 3.x base score of 5.5. It is not currently listed as actively exploited by CISA, and its EPSS exploit-prediction score is low. The underlying weakness is classified as CWE-755.

Key facts

Description

An Improper Handling of Exceptional Conditions vulnerability in the command-line processing of Juniper Networks Junos OS on SRX1500, SRX4100, and SRX4200 devices allows a local, low-privileged authenticated attacker executing the 'show chassis environment pem' command to cause the chassis daemon (chassisd) to crash and restart, resulting in a temporary Denial of Service (DoS). However, repeated execution of this command will eventually cause the chassisd process to fail to restart, impacting packet processing on the system. This issue affects Junos OS on SRX1500, SRX4100, SRX4200:  * All versions before 21.4R3-S9,  * from 22.2 before 22.2R3-S5,  * from 22.3 before 22.3R3-S4,  * from 22.4 before 22.4R3-S4,  * from 23.2 before 23.2R2-S3,  * from 23.4 before 23.4R2-S1.

Frequently asked questions

What is CVE-2025-21596?
An Improper Handling of Exceptional Conditions vulnerability in the command-line processing of Juniper Networks Junos OS on SRX1500, SRX4100, and SRX4200 devices allows a local, low-privileged authenticated attacker executing the 'show chassis environment pem' command to cause the chassis daemon (chassisd) to crash and restart, resulting in a temporary Denial of Service (DoS). However, repeated execution of this command will eventually cause the chassisd process to fail to restart, impacting packet processing on the system. This issue affects Junos OS on SRX1500, SRX4100, SRX4200:  * All versions before 21.4R3-S9,  * from 22.2 before 22.2R3-S5,  * from 22.3 before 22.3R3-S4,  * from 22.4 before 22.4R3-S4,  * from 23.2 before 23.2R2-S3,  * from 23.4 before 23.4R2-S1.
How severe is CVE-2025-21596?
CVE-2025-21596 has a CVSS 3.x base score of 5.5, rated medium severity. It is exploitable over local access with low attack complexity, requires low privileges and no user interaction. Impact on confidentiality is none, integrity none, and availability high.
Is CVE-2025-21596 being actively exploited?
It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (5th percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2025-21596?
CVE-2025-21596 primarily affects Juniper Junos. In total, 63 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.
How do I fix CVE-2025-21596?
Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround.
Does CVE-2025-21596 have an EU (EUVD) identifier?
Yes. CVE-2025-21596 is tracked in the ENISA EU Vulnerability Database (EUVD) as EUVD-2025-2563.
When was CVE-2025-21596 published?
CVE-2025-21596 was published on 2025-01-09 and last updated on 2026-06-17.

References

Affected products (63)

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